Use a Varien Data Collection with filters, sorts (orders) and limits

In a previous post, I shew how to create an Array attribute in Varien Object Class on Magento. Now it’s time to use your object in a Varien_Data_Collection.

When your create a Varien Data Collection, filters functions and others are defines, but contain nothing. They just return themselves. Here is a part of my code with some of these functions, it’s not complete, but you can check some of the functions :

INFO : This code is under construction, I have to create other filters and renderLimits !

Here is a function you have to put in your object class :

class MiniMax_MyModule_Model_MyObject extends Varien_Object{
	/*
	...
	*/

	public function getGeneric($field){return $this->{$field}; }

	/*
	...
	*/
}

If you find another solution to avoid this function, talk about it on the comments !

Now we create our custom collection inherit Varien_Data_Collection !

<?php 
class MiniMax_MyModule_Model_Collection_MyCollection extends Varien_Data_Collection{

	public function load($printQuery = false, $logQuery = false){
		// We add the renders
		$this->_renderFilters()->_renderOrders()->_renderLimit();
		parent::load($printQuery,$logQuery);
	}

	// This function is called by Magento when you type a text on a search field in a grid
	// $field : field we want to filter
	// $condition : Array ( [like] => Zend_Db_Expr Object ( [_expression:protected] => '%USER STRING%' ) ) 
	// It's the most classical type of condition, a string with a LIKE search like SQL, you can modify and 
	// complete the code to implements other filters, if you do this, tell me on comments!
    public function addFieldToFilter($field, $condition = null)
    {
		$keyFilter = key($condition);
		$valueFilter = $condition[$keyFilter]->__toString();
		$this->addFilter($field,$valueFilter,'and');
        return $this;
    }

	 protected function _renderFilters()
    {
		// If elements are already filtered, return this
        if ($this->_isFiltersRendered) {
            return $this;
        }

		foreach($this->_filters AS $filter){
			$keyFilter = $filter->getData()['field'];
			$valueFilter = substr($filter->getData()['value'],2,-2); // Delete '% AND %' of the string
			$condFilter = $filter->getData()['type']; // not used in this example

			// Loop you're item collection
			foreach($this->_items AS $key => $item){
				// NOTE : $item->getGeneric is a function in your object, i gave you the code at the top 
				//of the article

				// If it's not an array, we use the search term to compare with the value of our item
				if(!is_array($item->getGeneric($keyFilter))){
					if(!(strpos(strtolower($item->getGeneric($keyFilter)),strtolower($valueFilter)) !== FALSE)){
						unset($this->_items[$key]); 
						// If search term not founded, unset the item to 
						//not display it!
					}
				} else {
					// If it's an array
					$founded = false;
					foreach($item->getGeneric($keyFilter) AS $valeur){
						if(strpos(strtolower($valeur),strtolower($valueFilter)) !== FALSE){
							$founded = true;
						}
					}
					if(!$founded)
						unset($this->_items[$key]); // Not founded in the array, so unset the item
				}
			}

		}

		$this->_isFiltersRendered = true;
		return $this;
    }

    protected function _renderOrders()
    {		
		$keySort = key($this->_orders);
		$keyDirection = $this->_orders[$keySort];
		// We sort our items tab with a custom function AT THE BOTTOM OF THIS CODE
		usort($this->_items, $this->_build_sorter($keySort,$keyDirection));		
        return $this;
    }

	protected function _renderLimit()
    {
		/*
		I'm coding this part, COMING SOON ; )
		*/
        return $this;
    }

	protected function _build_sorter($key,$direction) {
		return function ($a, $b) use ($key,$direction) {
			if ($direction == self::SORT_ORDER_ASC)
				return strnatcmp($a[$key], $b[$key]); // Natural comparaison of string
			else 
				return -1 * strnatcmp($a[$key], $b[$key]); // reverse the result if sort order desc !
		};
	}

}

If you have some questions, or suggestions, comment the post, I am sure this code can be better 🙂